Episode 9: The Treatment of Symptomatic Hyponatremia with Hypertonic Saline with Jimmy Pruitt


Case Presentation

  • TF is a 58-year-old 50 kg female that presented to the ED with a chief complaint of progressively worsening weakness and fatigue over the past day since ingesting MDMA (Ecstasy) and increased fluid intake over last 24 hours. During the physical exam, TF started to have tonic-clonic seizures that lasted 2 minutes. The ED resident orders POC labs and the Na+ came back at 118 mEq/L.

 How do you treat this symptomatic hyponatremia?


  • Hyponatremia is defined as any serum sodium < 135 mEq/L.
  • Severe symptomatic hyponatremia typically occurs at a serum sodium < 120 mEq/L though the rapidity of the change in sodium is a key factor in the development of symptoms
  • Hyponatremia occurs in ~4% of adult patients that present to the ED

Signs and Symptoms

  • Mild/moderate Hyponatremia
    • Headache
    • Nausea/vomiting
    • Muscle cramps
    • Lethargy
    • Restlessness
  • Severe Hyponatemia
    • Disorientation
    • Focal neurologic deficits
    • Seizures (Status epilepticus common)
    • Coma


  • Often requires prompt correction
    • Fluid restriction and intravenous hypertonic saline
    • Reversible causes of hyponatremia corrected
    • Sodium deficit can be calculated to estimate replacement needs:
      • – Sodium deficit (mEq) = TBW x (desired Na – measured Na concentration)
        • TBWMEN = 0.6 L/kg x weight in kg
        • TBWWOMEN= 0.5 L/kg x weight in kg
        • May use adjusted body weight in obese
  • Treat neurologic emergencies with hypertonic saline
    • Hypertonic Saline 3%
      • 100-150 ml or 2ml/kg  over 10-30 minutes through a central OR peripheral line
    • Provide up to two additional 100-150 mL boluses, spaced 20 minutes apart, until a 5 mmol/L increase in sodium concentration is reached
  • Rapid correction of serum sodium by 2-3 mEq/L typically results in correction of neurologic emergency (particularly status epilepticus)
    • If symptoms do not improve continue IV 3% hypertonic saline at a rate leading to an increase of 1 mmol/L/hr.
      • This rate depends on each patient’s weight and percentage body water (see appendix for formula and example calculation)
    • Monitor sodium concentration every 4 hours
  • Do not exceed an increase of more than 10 mmol/L in 24 hours.

Alternative Therapy

  • 50 cc of 8.4% sodium bicarbonate (1 “ampule” of crash cart bicarb) q20-30 x 3 if symptoms do not improve

What About the Osmolarity of Hypertonic Saline?

Pharmacologic Agent Osmolality
3% NaCl 1027 mOsml/L
5% NaCL 1711 mOsm/L
7.5% Nacl 2,567 mOsm/L
8.4% Sodium bicarbonate 2000 mOsm/L
23.4% Nacl 8011 mOsm/L
D50W 2,525 mOsm/L
Etomidate 4,900 mOsm/L

Data For Use of 3% Hypertonic Saline Through a Peripheral Line

Protocols for 3% Hypertonic Saline




Pharmacy Related Considerations

  • Is there a protocol that guide the use of 3% NaCl for Symptomatic Hyponatremia?
    • Is the language clear on the recommendation on the type of line required vs recommended?
    • Is the protocol for ICP management?
    • Is the protocol for Hyponatremia?
  • Verifying 3% NaCl in the ED
    • A quick look at labs
    • The nursing note may have info about symptomatic hyponatremia
    • Quick Lit search if uncertain and no one to consult with
      • Institution guidelines, Tintinalli’s, Rosen’s, Uptodate, Pubmed, Societal Guidelines
    • When reaching out to team ask questions and be ready with a therapeutic alternative
  • 3% Hypertonic Saline through Peripheral Line?
    • Should be through a central line if one is available, however, 3% can and should be bolus on IV smart pump through a large Bore IV
  • Is 3% NaCl in your institutional automatic dispense cabinet? If not why? If not how quickly can it be obtained?

Nursing Considerations

  • Ask for clarification from experience nurse, pharmacist, and provider if there is confusion as to what is being asked of you and is this treatment appropriate
  • Be aware that this is a time-sensitive matter and newer healthcare professionals may be uncomfortable explaining why there’s confusion on the treatment plan
  • 18 G IV in the most distal access point
  • IV pump, pump tubbing, and no need for a filter, and have dedicated line for hypertonic initially
  • Nursing note with communication from Provider and description of what the symptoms of symptomatic hyponatremia

Physician Considerations

  • Clear communication about what you need the patient to receive
  • Realize that you may be the only one who’s comfortable with the treatment and let this be a teaching moment vs a screeching moment
  • Consider what labs can be done as a point of care (POC) and what labs need to be sent for go pass off to your consultant
  • Put in your CPOE order comment that “3% NaCl is for symptomatic Hyponatremia. Bolus required”
    • Helps pharmacy see whats it for and prompt quick lit search

Adverse Reactions

  • Rapid overcorrection of serum sodium can cause osmotic demyelination syndrome (ODS)
    • ODS can manifest as ataxia, quadraplegia, CN palsies or “locked-in” syndrome
    • Can occur up to 7 days after rapid correction
  • Preventing overcorrection
    • Do not increase serum sodium by more than 6-8 mEqL in the 1st 24 hours
    • Fluid restrict patient after relief of neurologic emergency
    • Monitor urine output (UO): If UO > 100 ml/hr, send urine osmolarity + urine sodium
    • Urine osmolarity < 100, give DDAVP 1 mcg
  • Correct Hypokalemia
    • Often will see hypokalemia in patients with severe hyponatremia
    • Correction of hypokalemia can improve hyponatremia
    • Oral repletion safe and efficacious if patient tolerating oral intake

Pharmacy Friday Pearls Handout


Related FOAM Posts







  1. Moritz ML and Ayus JC. 100 cc 3% sodium chloride bolus: a novel treatment for hyponatremic encephalopathy. Metab Brain Dis. 2010 Mar;25(1):91-6
  2. Ayus JC et al. Treatment of hyponatremic encephalopathy with a 3% sodium chloride protocol: a case series. Am J Kidney Dis. 2015 Mar;65(3):435-42.
  3. Achinger SG et al. Treatment of Hyponatremic Encephalopathy in the Critically Ill. Crit Care Med. 2017 Oct;45(10):1762-1771.
  4. Garrahy A et al. Continuous Versus Bolus Infusion of Hypertonic Saline in the Treatment of Symptomatic Hyponatremia Caused by SIAD.  J Clin Endocrinol Metab. 2019 Sep 1;104(9):3595-3602
  5. Kraft MD et al. Am J Health Syst Pharm. 2005; 62(16):1663-82.
  6. Sterns RH et al. Treating profound hyponatremia: a strategy for controlled correction. Am J Kidney Dis 2010; 56: 774-9.
  7. Verbalis JG et al. Diagnosis, evaluation, and treatment of hyponatremia: expert panel recommendations. Am J Med. 2013 Oct;126(10 Suppl 1):S1-42
  8. Mesghali E et al. Safety of Peripheral Line Administration of 3% Hypertonic Saline and Mannitol in the Emergency Department. J Emerg Med. 2019 Apr;56(4):431-436.
  9. Perez CA et al. Complication Rates of 3% Hypertonic Saline Infusion Through Peripheral Intravenous Access. J Neurosci Nurs. 2017 Jun;49(3):191-195.
  10. Meng L et al. Association between continuous peripheral i.v. infusion of 3% sodium chloride injection and phlebitis in adults. Am J Health Syst Pharm. 2018 Mar 1;75(5):284-291.
  11. Jones GM et al. Safety of Continuous Peripheral Infusion of 3% Sodium Chloride Solution in Neurocritical Care Patients. Am J Crit Care. 2016 Dec;26(1):37-42.
  12. Cooper DJ et al. Prehospital hypertonic saline resuscitation of patients with hypotension and severe traumatic brain injury: a randomized controlled trial. JAMA. 2004 Mar 17;291(11):1350-7.
  13. Harring TR et al. Emerg Med Clin N Am. 2014; 32(2):379-401.


Jimmy L. Pruitt III, PharmD, BCPS, BCCCP

The Pharm So Hard Podcast is a show focused primarily on emergency medicine and hospital pharmacy related topics. To empower healthcare providers with the knowledge and skills they need to provide evidence-based, safe care for critically ill patients.

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